Four objectives were planned for the entire project: (1) determination of the dissociation constants and related thermodynamic properties of biochemical buffers at different temperatures; (2) calculation of paH values for these buffers using a cell without liquid junction (based on the NBS Primary Standard Scale) in water and in isotonic saline; (3) computation of pH(s) values from the operational definition of pH for these buffers in water and in isotonic saline media with liquid junction; (4) comparison of the paH and pH(s) values for several different buffers, in an effort to establish a universal scale of pH. Part (1), (2), (3) and (4) remain to be performed during the upcoming year of research for the remaining buffers (ACES and Cholamine Chloride), whcih were proposed in the original program as being good prospective buffers, but have not as yet been throughly studied as part of this project. Also, paH and pH(s) values (that is, without and with liquid junction for ADA, will be determined at 25 degrees and 37 degrees C, since the results of pK2 of ADA have been reported from this laboratory in Anal. Chim. Acta.